Respiratory failure after hemorrhagic shock or trauma continues to be a major cause of morbidity and mortality. Currently, post shock pulmonary dysfunction is most frequently associated with an episode of sepsis in the post shock and resuscitation period. We have characterized the pulmonary microcirculatory response to shock alone. Our objective now is to characterize the response of the lung to the combined injury of shock and sepsis. We will utilize E Coli endotoxin as our septic insult. We will continuously monitor the protein permeability characteristics and fluid filtration ratio of the pulmonary microcirculation using the chronic lung lymph fistula preparation in the adult sheep. We will also be using lung lymph as a monitor of the etiology and degree of pulmonary cellular injury so as to better determine pathophysiology, by measuring the release of intracellular enzymes and vasoactive amines into the interstitial fluid.